title: Fetal and neonatal NK1.1+ Ly-49- cells can distinguish between major histocompatibility complex class I(hi) and class I(lo) target cells: evidence for a Ly-49-independent negative signaling receptor.
abstract: Natural killer (NK) cell function is regulated by both positive and negative signaling receptors. In adult splenic NK cells, negative signaling has been shown to be mediated by the Ly-49 family receptors. NK1.1- 2B4+ CD3- cells that are phenotypically and functionally similar to adult splenic NK cells can be derived from murine fetal liver and thymus. These cells do not express any known Ly-49 molecules on their surface nor do they contain the known Ly-49 transcripts. Surface expression of Ly-49 molecules is first detected on splenic NK1.1+ cells 4-6 days after birth. Despite the absence of these negative signaling receptors, fetal and neonatal Ly-49- NK cells lyse TAP-/- , major histocompatibility complex (MHC) class I(lo) but not TAP+/+, MHC class I(hi) target cells. This suggests that fetal and neonatal NK cells express negative signaling receptors other than Ly-49 molecules.
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235-9072, USA. sivakuma@utsw.swmed.edu
authors.forename: P V
authors.initials: PV
authors.lastname: Sivakumar
authors.forename: M
authors.initials: M
authors.lastname: Bennett
authors.forename: V
authors.initials: V
authors.lastname: Kumar
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000950:Antigens, Ly; D002454:Cell Differentiation; D002460:Cell Line; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D009928:Organ Specificity; D011971:Receptors, Immunologic / Q000276:immunology*; D055630:Receptors, NK Cell Lectin-Like; D015398:Signal Transduction / Q000276:immunology*
chemical_list: D000950:Antigens, Ly; D015395:Histocompatibility Antigens Class I; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like